FIG. 1 illustrates a concealed hinge device 100 of the prior art that includes a first hinge component 102 coupled to a second hinge component 102, and that is shown positioned for installation to hingeably couple a first planar substrate 120 to a second planar substrate 122 (e.g., respective aircraft cabinet wall and cabinet door panel components that may be constructed of honeycomb composite material). Also shown in FIG. 1 are block inserts 110 that each have a cavity 112 defined therein that is dimensioned to receive one of hinge components 102 in a manner so that face surface 103 of each of hinge components 102 is positioned flush coplanar arrangement with the face surface 105 of the corresponding block insert 110. A cavity 124 is in turn provided in each of face surfaces 130 of respective first and second substrates 120 and 122. Each cavity 124 is internally dimensioned to receive one of block inserts 110 so that face surface 105 of each of block inserts 110 is positioned flush coplanar arrangement with the face surface 105 of the corresponding block insert 110. Each block insert cavity 112 is further provided with two threaded openings 114 that are each configured to threadably receive a flathead screw fastener 108 when it is inserted through a corresponding opening 106 defined in one of hinge components 102 as shown in FIG. 1 in order to securably retain the given hinge component 102 within its corresponding block insert cavity 112. Each block insert cavity 110 is configured to be securably retained within its given substrate cavity 124 by applying epoxy adhesive compound to the block inserts 110 prior to inserting the block inserts 110 into cavities 124, and then allowing the adhesive to cure.
To assemble prior art hinge device 100 to first and second substrates 120 and 122, first and second block inserts 110 may first be inserted and secured within corresponding substrate cavities 124 of first and second substrates 120 and 122 by applying epoxy adhesive compound to blocks 110 and substrates 120 and 122. Next, a first one of hinge components 102 may be inserted and secured by two fasteners 108 within a cavity 112 of a first one of the block inserts 110 that has been previously secured within a first one of the substrates 120 or 122. The remaining second hinge component 102 may then be inserted into the remaining open second block insert cavity 112 by bringing the second substrate into angled adjacent position (as shown in FIG. 1). Two fasteners 108 may then be used to secure the second hinge component 102 within the cavity 112 of the second substrate. Because the face surface 103 of each of hinge components 102 is disposed in flush coplanar relationship with the corresponding adjacent face surfaces 105 and 130, substrates 120 and 122 are now hingeably coupled together in a manner so that hinge components 102 are concealed when first and second substrates 120 and 122 are rotated about hinge device 100 into end-to-end orientation with each other.